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Even though Republicans control the White House and both chambers of Congress, Washington remains a hostile place for any conservative determined to rein in federal government spending.

Just ask Sen. Tom Coburn, the freshman Republican from Oklahoma, who last week tried trimming $2.7 billion out of the $14 billion in special projects that the Senate loaded onto its “emergency” war spending bill.

Sitting in his office on a recent morning after two weeks of constant battle with Senate spenders, Mr. Coburn was upbeat over how much he had managed to save for the American taxpayer.

“Fifteen million,” he boasted wryly, fully grasping what a small dent that put in the $14 billion in added pork.

But he said there was a point anyway.

“But remember, we’re not measuring it that way,” he said of the staggering amount of pork that still got through. “This is a long-term strategy to change the behavior in the Congress and to change that behavior by exciting the American people and having them start paying attention. And they are.”

Mr. Coburn pointed to a poll conducted by the Wall Street Journal that showed the No. 1 priority American voters have for Congress is ending the process of “earmarks,” the special projects that members of Congress insert into spending bills to curry political favor.

That the issue has become of such urgent concern to voters is in no small measure because of the single-minded efforts of Mr. Coburn, who won election to the Senate just two years ago. Before that, he entered the House as one of the Republican “Class of 1994,” but left in 2001, keeping his pledge to serve only three terms.

That the issue has become of such urgent concern also has to do with the extravagant examples of pork that Mr. Coburn has hauled out of the shadows, onto the Senate floor and for days ridiculed on national television.

Mr. Coburn called it outrageous to saddle taxpayers in all 50 states with a bill for $700 million for moving a railroad in Mississippi that helps few outside that state other than wealthy railroad companies.

“So, if we educate the American people enough to where they ask good questions, you can’t defend it,” he said.

When Mr. Coburn picks a fight with one of his colleagues over spending, he doesn’t look for someone smaller than himself. Rather, he has always gone after the biggest and strongest in the room: the men who have led the Senate Appropriations Committee.

Last year, there was the famous “bridge to nowhere,” a $230 million project inserted into a transportation bill by former Appropriations Chairman Ted Stevens of Alaska. The bridge would connect a remote island with 50 residents to another remote Alaska island.

Mr. Stevens ultimately succeeded in getting the money for his state, but only after a screaming temper tantrum on the Senate floor, in which the No. 3 Republican threatened to quit the Senate over Mr. Coburn’s efforts.

“I was worried I was going to have to resuscitate him on the floor,” said Mr. Coburn, who is a doctor.

And there was the “train to nowhere,” the $700 million project inserted into last week’s “emergency” war spending bill by the new Appropriations chairman, Thad Cochran of Mississippi.

“He’s working hard for Mississippi,” Mr. Coburn said of the chairman. “I just don’t think some of the stuff is a legitimate cost for the federal taxpayer.”

While Mr. Coburn is utterly unapologetic for his crusade or his disruptive manner of pursuing it, he seems perfectly aware that he is regarded with some suspicion among his buttoned-down Senate colleagues.

“You know, it’s irritating to a chairman to have some young punk come up and challenge what you’re doing and challenge the system that’s been working here for a number of years,” he said. “I understand that.”

Along the way, Mr. Coburn has found allies among some Democrats, such as Sen. Russ Feingold of Wisconsin.

Mr. Coburn said he tried to appeal to liberals that if they want government more involved in people’s lives, the best way to do that is to make the government less wasteful.

“Unless we control spending, the very things they want to do for people aren’t going to be available,” Mr. Coburn said. “What I hope to do is build a relationship with conservatives and liberals that recognizes that our financial status is so dire that we have to work together.”

Mr. Coburn’s mission also means he’s not exactly a blind cheerleader for Republicans.

Asked whether there would be any advantage for conservatives if Republicans lost control of Congress in November’s elections, Mr. Coburn replied, “We have a wonderful republic. How do we preserve that? I don’t know the answer to that question, but I do know the collective wisdom at the polls most often is better than our collective wisdom here.”